================================================================== BUG: KASAN: use-after-free in tcp_skb_pcount include/net/tcp.h:798 [inline] BUG: KASAN: use-after-free in tcp_init_tso_segs net/ipv4/tcp_output.c:1631 [inline] BUG: KASAN: use-after-free in tcp_write_xmit+0x3b22/0x4680 net/ipv4/tcp_output.c:2068 Read of size 2 at addr ffff8800b4aca7b0 by task syz-executor4/7044 CPU: 0 PID: 7044 Comm: syz-executor4 Not tainted 4.4.163+ #122 0000000000000000 47659fb82d4a2a8d ffff8800af8078d0 ffffffff81aa556d ffffea0002d2b280 ffff8800b4aca7b0 0000000000000000 ffff8800b4aca7b0 dffffc0000000000 ffff8800af807908 ffffffff8148a8db ffff8800b4aca7b0 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [] print_address_description+0x6c/0x217 mm/kasan/report.c:252 [] kasan_report_error mm/kasan/report.c:351 [inline] [] kasan_report.cold.6+0x175/0x2f7 mm/kasan/report.c:408 [] __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:427 [] tcp_skb_pcount include/net/tcp.h:798 [inline] [] tcp_init_tso_segs net/ipv4/tcp_output.c:1631 [inline] [] tcp_write_xmit+0x3b22/0x4680 net/ipv4/tcp_output.c:2068 [] __tcp_push_pending_frames+0xa4/0x2a0 net/ipv4/tcp_output.c:2319 [] tcp_sendmsg+0x21a3/0x2b30 net/ipv4/tcp.c:1272 [] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755 [] sock_sendmsg_nosec net/socket.c:638 [inline] [] sock_sendmsg+0xbb/0x110 net/socket.c:648 [] SYSC_sendto net/socket.c:1678 [inline] [] SyS_sendto+0x220/0x370 net/socket.c:1646 [] entry_SYSCALL_64_fastpath+0x1e/0x9a Allocated by task 7044: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack mm/kasan/kasan.c:512 [inline] [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:616 [] kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:601 [] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554 [] slab_post_alloc_hook mm/slub.c:1349 [inline] [] slab_alloc_node mm/slub.c:2615 [inline] [] slab_alloc mm/slub.c:2623 [inline] [] kmem_cache_alloc+0xdc/0x2c0 mm/slub.c:2628 [] kmem_cache_alloc_node include/linux/slab.h:350 [inline] [] __alloc_skb+0xe6/0x5b0 net/core/skbuff.c:218 [] alloc_skb_fclone include/linux/skbuff.h:856 [inline] [] sk_stream_alloc_skb+0xa3/0x5d0 net/ipv4/tcp.c:833 [] tcp_sendmsg+0xf81/0x2b30 net/ipv4/tcp.c:1178 [] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755 [] sock_sendmsg_nosec net/socket.c:638 [inline] [] sock_sendmsg+0xbb/0x110 net/socket.c:648 [] SYSC_sendto net/socket.c:1678 [inline] [] SyS_sendto+0x220/0x370 net/socket.c:1646 [] entry_SYSCALL_64_fastpath+0x1e/0x9a Freed by task 7039: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack mm/kasan/kasan.c:512 [inline] [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_slab_free+0xac/0x190 mm/kasan/kasan.c:589 [] slab_free_hook mm/slub.c:1383 [inline] [] slab_free_freelist_hook mm/slub.c:1405 [inline] [] slab_free mm/slub.c:2859 [inline] [] kmem_cache_free+0xbe/0x350 mm/slub.c:2881 [] kfree_skbmem+0xcf/0x100 net/core/skbuff.c:635 [] __kfree_skb+0x1d/0x20 net/core/skbuff.c:676 [] sk_wmem_free_skb include/net/sock.h:1447 [inline] [] tcp_write_queue_purge include/net/tcp.h:1460 [inline] [] tcp_connect_init net/ipv4/tcp_output.c:3134 [inline] [] tcp_connect+0xae9/0x3110 net/ipv4/tcp_output.c:3273 [] tcp_v4_connect+0xf31/0x1890 net/ipv4/tcp_ipv4.c:246 [] __inet_stream_connect+0x2a9/0xc30 net/ipv4/af_inet.c:615 [] inet_stream_connect+0x55/0xa0 net/ipv4/af_inet.c:676 [] SYSC_connect net/socket.c:1570 [inline] [] SyS_connect+0x1b8/0x310 net/socket.c:1551 [] entry_SYSCALL_64_fastpath+0x1e/0x9a The buggy address belongs to the object at ffff8800b4aca780 which belongs to the cache skbuff_fclone_cache of size 456 The buggy address is located 48 bytes inside of 456-byte region [ffff8800b4aca780, ffff8800b4aca948) The buggy address belongs to the page: BUG: unable to handle kernel paging request at fffffffcff1a2b80 IP: [] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247 PGD 2e0d067 PUD 0 Oops: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 1 PID: 2130 Comm: syz-executor4 Not tainted 4.4.163+ #122 task: ffff8801d42117c0 task.stack: ffff8801c2778000 RIP: 0010:[] [] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247 RSP: 0018:ffff8801c277f828 EFLAGS: 00010046 RAX: 1ffffffff05d2a0b RBX: 00000000000181a8 RCX: ffffffff831a2900 RDX: fffffbff9fe34570 RSI: fffffffcff1a2b80 RDI: ffffffff82e95058 RBP: ffff8801c277f868 R08: ffff8801d4212088 R09: 01d03681800360cf R10: ffff8801d42117c0 R11: 0000000000000001 R12: ffffffff82e94f80 R13: dffffc0000000000 R14: 00000000069354cf R15: ffffffffaf800050 FS: 0000000000000000(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffffcff1a2b80 CR3: 0000000002e0a000 CR4: 00000000001606b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff811f0c80 0000000000000046 0000000000000003 ffff8800a67bc7a0 ffff8800a67bc740 00000000069354cf ffff8800a67bc7f0 0000000000000000 ffff8801c277f8b0 ffffffff8117c469 ffffffff82c489d8 ffffffff811fb5d0 Call Trace: [] update_curr+0x2c9/0x6d0 kernel/sched/fair.c:882 [] enqueue_entity kernel/sched/fair.c:3512 [inline] [] enqueue_task_fair+0x12a/0xab90 kernel/sched/fair.c:4711 [] enqueue_task kernel/sched/core.c:858 [inline] [] activate_task+0x1dd/0x280 kernel/sched/core.c:874 [] ttwu_activate kernel/sched/core.c:1736 [inline] [] ttwu_do_activate.constprop.29+0xbf/0x1e0 kernel/sched/core.c:1789 [] ttwu_queue kernel/sched/core.c:1934 [inline] [] try_to_wake_up+0x6dd/0x1120 kernel/sched/core.c:2068 [] wake_up_state+0x10/0x20 kernel/sched/core.c:2148 [] signal_wake_up_state+0x44/0x70 kernel/signal.c:659 [] signal_wake_up include/linux/sched.h:3332 [inline] [] complete_signal+0x635/0x7b0 kernel/signal.c:942 [] __send_signal+0x57f/0x1280 kernel/signal.c:1080 [] send_signal+0x4a/0xc0 kernel/signal.c:1096 [] do_send_sig_info+0xa4/0x130 kernel/signal.c:1151 [] send_sig_info+0x33/0x50 kernel/signal.c:1436 [] zap_pid_ns_processes+0x28d/0x690 kernel/pid_namespace.c:223 [] find_child_reaper kernel/exit.c:477 [inline] [] forget_original_parent kernel/exit.c:563 [inline] [] exit_notify kernel/exit.c:599 [inline] [] do_exit+0x1d99/0x29a0 kernel/exit.c:776 [] do_group_exit+0x111/0x300 kernel/exit.c:885 [] SYSC_exit_group kernel/exit.c:896 [inline] [] SyS_exit_group+0x1d/0x20 kernel/exit.c:894 [] entry_SYSCALL_64_fastpath+0x1e/0x9a Code: 49 8d bc 24 d8 00 00 00 48 89 f8 48 c1 e8 03 42 80 3c 28 00 0f 85 c4 01 00 00 49 8b 9c 24 d8 00 00 00 80 3a 00 0f 85 8f 01 00 00 <4a> 03 1c f9 48 89 d8 48 c1 e8 03 42 80 3c 28 00 0f 85 be 01 00 RIP [] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247 RSP CR2: fffffffcff1a2b80 ---[ end trace fa392a481816cb0e ]---